Cytokine blockade is a promising way to reduce inflammation and suffering in acute and chronic inflammatory conditions such as rheumatoid arthritis or colitis. Passive protection, e.g. injection of antibodies or receptor antagonists to bock the cytokines TNF- or IL-1, respectively, is a well-established treatment for these conditions, but requires frequent patient monitoring and daily or weekly injections of large quantities of expensive biologics, and it can eventually fail due to sensitization of the patient's immune system to the therapeutic protein. Alternatively, immunotherapies that generate neutralizing antibody responses against cytokines are being pursued as more efficient strategies for protection, but have been challenging because the antibodies must be raised without breaking T cell tolerance to the cytokines, which could cause an irreversible response and ongoing inflammation in cytokine-producing tissues. The goal of this project is to develop a novel, modular, chemically defined biomaterial that can generate neutralizing antibody responses in situ against specific cytokines without inflammation or breaking T cell tolerance to those cytokines. The strategy employs self-assembling peptides that can incorporate precise ratios of epitopes of interest and generate targeted antibody responses in the absence of inflammation. This proposal will test the hypothesis that immunization with co-assembled peptide fibers displaying B cell epitopes from an inflammatory cytokine, TNF- or IL-1, alongside a non-cytokine T cell epitope will generate therapeutic antibody responses against the cytokine without inducing inflammation or T cell responses to the cytokine. Preliminary data using model antigens support this hypothesis. Self-assemblies of cytokine peptide epitopes will be synthesized, tested for co-assembly with an established universal T cell epitope, and tested for their ability to raise high-titer antibody responses in healthy mice (Aim 1). Next, the materials wll be optimized for effectiveness, first using an in vitro assay of neutralization of cytokine bioactivity by sera collected from immunized mice, then using an in vivo assay of protection against cytokine-mediated endotoxic shock (Aim 2). This materials-based strategy for cytokine immunotherapy is an innovative approach for managing inflammatory conditions, exploiting the ability of peptide-self-assemblies to raise targeted antibody responses without associated inflammation. This R21 project will serve as a critical proof-of-concept that durable and therapeutic anti-cytokine responses can be induced via chemically defined peptide materials, thus establishing a versatile platform for further development within disease-specific contexts of rheumatoid arthritis, colitis, or other inflammatory diseases.